Bais HP, Sudha GS, Ravishankar GA
Department of Plant Cell Biotechnology, Central Food Technological Research Institute, Mysore 570 013, India
J Plant Growth Regul. 2000 Jun;19(2):238-248. doi: 10.1007/s003440000012.
The influence of putrescine (Put) and AgNO(3) on shoot multiplication, in vitro flowering and endogenous titers of polyamines in Cichorium intybus L. cv. Lucknow local was investigated. Exogenous administration of Put at a concentration of 40 mM resulted in maximum tissue response in terms of shoot numbers (34.6 +/- 2.61) and shoot lengths (7.6 +/- 0.57 cm) on MS media supplemented with 2-iP (2.0 mg L(-1)) and GA(3) (0.5 mg L(-1)) as observed on the 35(th) day. Exogenous application of 40 µM AgNO(3) resulted in maximum shoot number (36.8 +/- 2.63) and shoot lengths (7.9 +/- 0.76 cm) on day 35 on the same media. Endogenous titers of conjugated spermidine decreased sharply from day 7-21, whereas endogenous conjugated spermine levels peaked on day 28 (1265 +/- 94.9 nmoles g(-1) FW), after treatment with 40 mM Put. Whereas, AgNO(3) (40 µM) fed samples resulted in higher titers of endogenous conjugated spermine (1405 +/- 105.6 nmoles g(-1) FW, 3.62 fold over control) on day 14. All other treatments showed decreasing endogenous levels during the whole culture period. Both Put (40 mM) and AgNO(3) (40 µM) resulted in floral initiation and floral development on day 28 and 14 (3.76 +/- 0.16, 4.2 +/- 0.21 flowers per shoot apices), respectively. To investigate the role of Put (40 mM) and AgNO(3) (40 µM) on morphogenetic response and endogenous conjugated polyamine titers in shoots of chicory, polyamine inhibitors (DFMA and DFMO) were used. The morphogenetic response and the endogenous conjugated pool of polyamines were diminished in DFMA and DFMO treatments, but could be restored by addition of Put (40 mM) and AgNO(3) (40 µM). Under exogenous Put feeding, ethylene production was reduced in shoot cultures of chicory. This study shows for the first time the influence of polyamines on multiple shoot initiation from axillary buds of C. intybus L. cv. Lucknow local and also indicates the promotive effect of Put and AgNO(3) on autoregulation of polyamine biosynthesis, thereby regulating in vitro flowering, the endogenous pool of polyamines and shoot multiplication.
研究了腐胺（Put）和硝酸银（AgNO₃）对菊苣品种勒克瑙本地种芽增殖、离体开花及多胺内源含量的影响。在添加了2-异戊烯腺嘌呤（2.0 mg L⁻¹）和赤霉素（GA₃，0.5 mg L⁻¹）的MS培养基上，第35天时，外源施加浓度为40 mM的腐胺，芽数（34.6 ± 2.61）和芽长（7.6 ± 0.57 cm）方面的组织反应达到最大值。在相同培养基上，第35天时，外源施加40 μM硝酸银，芽数（36.8 ± 2.63）和芽长（7.9 ± 0.76 cm）达到最大值。用40 mM腐胺处理后，结合亚精胺的内源含量在第7至21天急剧下降，而结合精胺的内源水平在第28天达到峰值（1265 ± 94.9 nmol g⁻¹鲜重）。而用40 μM硝酸银处理的样品在第14天时，结合精胺的内源含量更高（1405 ± 105.6 nmol g⁻¹鲜重，是对照的3.62倍）。所有其他处理在整个培养期间内源水平均呈下降趋势。腐胺（40 mM）和硝酸银（40 μM）分别在第28天和第14天导致花芽起始和花芽发育（每个茎尖分别有3.76 ± 0.16朵和4.2 ± 0.21朵花）。为了研究40 mM腐胺和40 μM硝酸银对菊苣芽形态发生反应和内源结合多胺含量的作用，使用了多胺抑制剂（二氟甲基精氨酸和二氟甲基鸟氨酸）。在二氟甲基精氨酸和二氟甲基鸟氨酸处理中，形态发生反应和多胺的内源结合库减少，但通过添加40 mM腐胺和40 μM硝酸银可恢复。在外源施加腐胺的情况下，菊苣茎段培养物中的乙烯产量降低。本研究首次表明多胺对菊苣品种勒克瑙本地种腋芽多芽起始的影响，还表明腐胺和硝酸银对多胺生物合成的自动调节具有促进作用，从而调节离体开花、多胺的内源库和芽增殖。
